James
Cook University scientists have found lizards exposed to rain, hail and shine
may cope better with extreme weather events predicted as a result of climate
change than their fair-weather cousins.

A
new study by JCU PhD student Anna Pintor, published in the journal Ecological
Monographs, is one of the first to test the Climatic Variability Hypothesis
(CVH) – which proposes that animals
living in environmentally variable areas should be able to tolerate more
environmental fluctuations as a result.

This
idea is a key assumption of the controversial Rapoport’s Rule – which states
that a species at higher latitudes with variable weather conditions leads to
the evolution of wider environmental tolerances which leads to a requirement
for a larger range size.

Ms Pintor, along with supervisors Professor Lin Schwarzkopf and Professor
Andrew Krockenberger from the Centre for Tropical Biodiversity and Climate
Change, used three groups of Australian skinks for their analysis.

Their results
confirm, in all three groups, that species living in regions with greater
temperature variability have both greater environmental tolerances and wider
ranges – both in terms of latitude and altitude.

Andrew
Krockenberger explains the importance of this result to advancing scientific
thought “The literature is full of examples of species that do and don’t fit
Rapoport’s rule,” he said. “We’ve shown
what is important is the actual underlying mechanism – that species that can
deal with a high degree of variability at a single site also end up with more
extensive geographic ranges.

“Arguing
about whether or not Rapoport's rule is valid is irrelevant and misses the
point – let’s start making sure we understand the underlying process instead.”

Lead
author Anna Pintor said if we want to understand impacts of climate change
in the future, we need to know how species' current distributions come about it
the first place.

“Understanding underlying mechanisms like the
CVH is one way to do that, but we need to do a
lot more before we can tell exactly how species will be impacted and how to
best help them deal with climate change.”